The present invention relates to labelling machines for applying strip labels and in particular wraparound labels. The machine is designed to cut a label from a label supply and then adhesively secure the label to an article such as a bottle.
Labelling machines using material feed from a bulk roll continue to gain market acceptance due to the low cost of the label supply as well as the excellent print characteristics that can be obtained. The labels are supplied in roll form and the strip of labels is advanced and cut to the correct label length. The label is then transferred by a vacuum drum past an adhesive station in preparation for transfer to a synchronized article to be labelled. The labels are typically made of a thin plastic film. These machines must also address the problems of applying glue to various portions of the label and/or all of the label, and normally have some capability for varying the length of label to be applied as required for different product sizes. One particular labelling machine uses a vacuum drum having outward deformations at what would be the leading and trailing edge of a label appropriately positioned thereon, such that the outward deformations force this limited portion of the label against a glue column or glue roll as it is transferred from the label supply to the article to be labelled. In the event that a label is not present on the drum, the glue roller is retracted and must be repositioned to resume the labelling cycle. In order to vary the machine for different length labels, the entire vacuum drum is replaced. It is also necessary in some application to provide a high speed labelling machine which is still capable of applying the labels with the same degree of accuracy, or at least to produce a satisfactory product. It must be noted that wrap labels represent a major portion of the appearance of the product and as such, the labelling process must be reliable.
There remains a need for a reliable, flexible apparatus having improvements with respect to the application of glue to the leading and trailing edges of a label or various portions of the label as well as simplified adjustment to effect changeover from one label length to another.
In high speed applications, further control of the spacing and vertical aligning of the article to be labelled is necessary to effect the required control to assure proper synchronization of the article to be labelled and the label. In a preferred embodiment of the invention, a pocket wheel and feed screw are combined at the infeed of the machine to provide greter precision.